ARNOTTO, or Annatto, is a dyeing material produced from the seeds of Bixa Orellana (Nat. Ord. Flacovrtiaceaι), a small tree which grows in Central and South America. The seeds are surrounded with a thin coating of a waxy pulp, which is separated from them by washing in water, passing the liquid through a sieve, and allowing the suspended pulp to deposit. The water is then drained away and the paste dried, till it is a thick, stiff, unctuous mass. In this state it has a dark orange-red colour, and is known as “roll” or “flag” arnotto, according to the form in which it is put up, but when further dried it is called “cake” arnotto. Arnotto is much used by South American Indians for painting their bodies; among civilised communities its principal use is for colouring butter, cheese, and varnishes. It yields a fugitive bright orange colour, and is to some extent used alone, or in conjunction with other dyes, in the dyeing of silks and in calico printing.